#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
	int n;
	cin >> n;
	int m = n;
	double sum = 0;
	while (n--)
	{
		double x;
		cin >> x;
		sum = sum + x;
	}
	cout <<fixed<<setprecision(2)<< sum / m;
	return 0;
}